Soluble Proteins in Different Levels of the Epidermis

Abstract

The soluble proteins of the epidermis received little attention in the past and their nature is not well known. Early work in this field was done by Spier, Rockl and Early (1) who used heat separated human epidermis for their studies and extracted the soluble proteins with physiological saline solution. Paper electrophoresis revealed a fast moving band and a slow one, the latter consisting of several subcomponents. Whereas the fast moving band migrated with the speed of serum albumin, the slow one migrated with that of serum globulins. Matoltsy and Herbst (2, 3) extracted the isolated human epidermis with neutral phosphate buffer, or acetate buffer of pH 8.6 or 1 M buffered sodium chloride solution. Paper electrophoresis showed that each of these extracts contain two main components: (1) a fast moving small component, and (2) a relatively slow moving large component. The soluble proteins of the epidermis were more recently studied by a variety of technics in different vertebrates by Baden and Freedberg (4). These workers used guinea pig, pig, rabbit and human skin and separated the epidermis from the dermis by heat treatment or the stretch method. The proteins were extracted with neutral phosphate buffer and analyzed by paper, starch or agar gel electrophoresis. It was noted that the extracts contain serum albumin, a2 and y globulins. Furthermore, whereas agar gel electrophoresis indicated three proteins distinct from serum proteins, immunological technics revealed four distinct epidermal proteins in the extracts.